Mobile communications systems continue to grow in popularity and have become an integral part of both personal and business communications. Mobile telephones allow users to place and receive voice calls most anywhere they travel. Moreover, as mobile telephone technology has increased, so too has the functionality of mobile devices and the different types of devices available to users. For example, many mobile devices now incorporate personal digital assistant (PDA) features such as calendars, address books, task lists, etc. Moreover, such multi-function devices may also allow users to wirelessly send and receive electronic mail (email) messages and access the Internet via a cellular network and/or a wireless local area network (WLAN), for example.
As a result, users continue to spend more time using their mobile devices during the course of a day performing information searches, reading emails, etc., as opposed to early cellular phones that were used only for phones calls. This has resulted in a significant interest from the advertising community in targeting advertisements to mobile devices.